Preperation of unbranched glucans by hydrolysis of starch of various botanical origin with pullulanase

The use of pullulanase preparation was checked as a method to obtain long unbranched glucans from native starch. Different starch sources as well as various solubilisation procedures were tried in order to choose the optimal one. Dissolving in NaOH proved to be suitable for all starch sources, while autoclave should be avoided in case of cereal starches. Potato starch gave clear solutions irrespective of solubilisation method, which were highly susceptible to enzymatic attack. Basing on the results obtained by size exclusion chromatography it was concluded that the time of incubation with the enzyme needed to completely degrade amylopectin molecules is short in comparison to the time needed to hydrolyse all available glycosidic bonds.